问题补充：
He used to in the day, but he is used to at night.
A. read ; read
B. reading; read
C. read; reading
D. reading; reading
答案：
A. read ; read
B. reading; read
(答案→)C. read; reading
D. reading; reading
解析：used to do sth 过去常常做某事；be used to sth/doing sth 习惯于某事/做某事。句意：他过去常常在白天读书，但是他现在习惯了晚上读书。故选C。
